Flexible printed wiring board, joined body, pressure sensor and mass flow controller

Abstract

In a flexible printed wiring board ( 1 ), a first electrical conduction pattern ( 4 ) prepared on the first surface ( 3 a ) on which a bare chip ( 2 ) is mounted is prepared only inside a mounting region ( 3 c ) of the bare chip. Preferably, the first electrical conduction patterns ( 4 ) are prepared so as to avoid positions opposite to test electrodes ( 2 b ) which the bare chip comprises. Thereby, in the flexible printed wiring board used for mounting the bare chip, occurrence of malfunction resulting from electrical connection with a part other than a bump of the bare chip can be certainly prevented, and reliability of various devices using the bare chip can be improved.

The invention claimed is: 
     
       1. A flexible printed wiring board having:
 an insulation substrate comprising a first surface that is a surface on which a bare chip is mounted and a second surface that is a surface located on an opposite side of said first surface; 
 one or more first electrical conduction patterns which are prepared on said first surface and include first electrode parts arranged at positions where the first electrode part can be electrically connected with a bump of said bare chip in a mounted state that is a state where said bare chip is mounted on said first surface; 
 one or more through holes drilled in said insulation substrate, and 
 one or more second electrical conduction patterns prepared on said second surface; 
 wherein: 
 at least a part of said first electrical conduction patterns further comprise a first electrical conduction part that is a part for electrically connecting said first electrode part with said through hole; 
 at least a part of said first electrical conduction patterns and at least a part of said second electrical conduction patterns are electrically connected with each other through said through holes; and 
 said first electrical conduction patterns are prepared only inside a mounting region that is a region opposite to said bare chip in said mounted state. 
 
     
     
       2. The flexible printed wiring board according to  claim 1 , wherein:
 said first electrical conduction patterns comprise one or more first lands; 
 said second electrical conduction patterns comprise one or more second lands; and 
 said first lands and said second lands are electrically connected with each other through said through holes. 
 
     
     
       3. The flexible printed wiring board according to  claim 2 , comprising:
 an insulating layer prepared so as to cover at least a part of said second electrical conduction patterns. 
 
     
     
       4. The flexible printed wiring board according to  claim 3 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       5. The flexible printed wiring board according to  claim 2 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       6. The flexible printed wiring board according to  claim 1 , comprising:
 an insulating layer prepared so as to cover at least a part of said second electrical conduction patterns. 
 
     
     
       7. The flexible printed wiring board according to  claim 6 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       8. The flexible printed wiring board according to  claim 1 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       9. The flexible printed wiring board according to  claim 1 , wherein:
 said bare chip comprises test electrodes, and 
 said first electrical conduction patterns are prepared so as to avoid a position opposite to said test electrode. 
 
     
     
       10. The flexible printed wiring board according to  claim 9 , wherein:
 said first electrical conduction patterns comprise one or more first lands; 
 said second electrical conduction patterns comprise one or more second lands; and 
 said first lands and said second lands are electrically connected with each other through said through holes. 
 
     
     
       11. The flexible printed wiring board according to  claim 10 , comprising:
 an insulating layer prepared to cover at least a part of said second electrical conduction patterns. 
 
     
     
       12. The flexible printed wiring board according to  claim 11 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       13. The flexible printed wiring board according to  claim 10 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       14. The flexible printed wiring board according to  claim 9 , comprising:
 an insulating layer prepared so as to cover at least a part of said second electrical conduction patterns. 
 
     
     
       15. The flexible printed wiring board according to  claim 14 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       16. The flexible printed wiring board according to  claim 9 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       17. A joined body comprising:
 a flexible printed wiring board; and 
 a bare chip; 
 wherein the flexible printed wiring board comprises:
 an insulation substrate comprising a first surface that is a surface on which a bare chip is mounted and a second surface that is a surface located on an opposite side of said first surface; 
 one or more first electrical conduction patterns which are prepared on said first surface and include first electrode parts arranged at positions where the first electrode part can be electrically connected with a bump of said bare chip in a mounted state that is a state where said bare chip is mounted on said first surface; 
 one or more through holes drilled in said insulation substrate; and 
 one or more second electrical conduction patterns prepared on said second surface; 
 wherein: 
 at least a part of said first electrical conduction patterns further comprise a first electrical conduction part that is a part for electrically connecting said first electrode part with said through hole; 
 at least a part of said first electrical conduction patterns and at least a part of said second electrical conduction patterns are electrically connected with each other through said through holes; and 
 said first electrical conduction patterns are prepared only inside a mounting region that is a region opposite to said bare chip in said mounted state. 
 
 
     
     
       18. The joined body according to  claim 17 , wherein:
 said bare chip comprises test electrodes, and 
 said first electrical conduction patterns are prepared so as to avoid a position opposite to said test electrode. 
 
     
     
       19. The joined body according to  claim 17 , wherein:
 said first electrical conduction patterns comprise one or more first lands; 
 said second electrical conduction patterns comprise one or more second lands; and 
 said first lands and said second lands are electrically connected with each other through said through holes. 
 
     
     
       20. The joined body according to  claim 17 , comprising:
 an insulating layer prepared to cover at least a part of said second electrical conduction patterns. 
 
     
     
       21. The joined body according to  claim 17 , wherein:
 said second electrical conduction pattern comprises a second electrode part for electrically connecting with an external electrode. 
 
     
     
       22. The joined body according to  claim 17 , wherein:
 an electrical connection between said bump ( 2   a ) and said first electrode part ( 4   a ) is attained by an anisotropic conductive film. 
 
     
     
       23. A pressure sensor comprising:
 a flexible printed wiring board; and 
 a strain sensor; 
 
       wherein the flexible printed wiring board comprises:
 an insulation substrate comprising a first surface that is a surface on which said strain sensor is mounted and a second surface that is a surface located on an opposite side of said first surface; 
 one or more first electrical conduction patterns which are prepared on said first surface and include first electrode parts arranged at positions where the first electrode part can be electrically connected with a bump of said strain sensor in a mounted state that is a state where said strain sensor is mounted on said first surface; 
 one or more through holes drilled in said insulation substrate, and 
 one or more second electrical conduction patterns prepared on said second surface; 
 wherein: 
 at least a part of said first electrical conduction patterns further comprise a first electrical conduction part that is a part for electrically connecting said first electrode part with said through hole; 
 at least a part of said first electrical conduction patterns and at least a part of said second electrical conduction patterns are electrically connected with each other through said through holes; and
 said first electrical conduction patterns are prepared only inside a mounting region that is a region opposite to said strain sensor in said mounted state. 
 
 
     
     
       24. The pressure sensor of  claim 23 , wherein:
 an electrical connection between said bump and said first electrode part is attained by an anisotropic conductive film. 
 
     
     
       25. A mass flow controller comprising:
 a pressure sensor comprising:
 a flexible printed wiring board; and 
 a strain sensor; 
 
 
       wherein the flexible printed wiring board comprises:
 an insulation substrate comprising a first surface that is a surface on which said strain sensor is mounted and a second surface that is a surface located on an opposite side of said first surface; 
 one or more first electrical conduction patterns which are prepared on said first surface and include first electrode parts arranged at positions where the first electrode part can be electrically connected with a bump of said strain sensor in a mounted state that is a state where said strain sensor is mounted on said first surface; 
 one or more through holes drilled in said insulation substrate, and 
 one or more second electrical conduction patterns prepared on said second surface; 
 wherein: 
 at least a part of said first electrical conduction patterns further comprise a first electrical conduction part that is a part for electrically connecting said first electrode part with said through hole; 
 at least a part of said first electrical conduction patterns and at least a part of said second electrical conduction patterns are electrically connected with each other through said through holes; and 
 said first electrical conduction patterns are prepared only inside a mounting region that is a region opposite to said strain sensor in said mounted state; and 
 means for monitoring pressure of fluid by said pressure sensor. 
 
     
     
       26. The mass flow controller of  claim 25 , wherein:
 an electrical connection between said bump and said first electrode part is attained by an anisotropic conductive film.